Chinook RV

Okay, I think I'm on the right track now. What was confusing is that they took the smaller red wire and spliced in a black fuse line wire. I found that after unwrapping them. Now in the process of tracking the red wire back to the controller.

After tearing half the van apart in an attempt to run a new positive (red) wire, I discovered that the black ground inside the conduit was detached.
Thanks everyone for your help, it got me on the right course.

I had a similar problem when I bought my 2000 coach new.
I found that the ground connection (negative from The house
batteries) located on the chassis behind the battery compartment
was faulty. When the factory installed the ground connections
they used a power drill to drill and secure the screw and used
too much torque resulting in partially twisting the attaching screw.
As a result, the screw eventually rusted not making a connection.
This was also true for the ground connections (on my Concourse)
at the two rear corners. I removed all of the ground connections,
re-drilled the chassis holes, cleaned the connection area, and
re-attached the connections with stainless hardware. I have not
had any problems since. Therefore, I would check those connections.

Thanks, there were two leads going into the house battery ground. They were in a plastic casing so I couldn't see that the ground from the controller was not attached. Problem solved. Now to replace everything I took apart trying to track wires looking for a break.